[Shadows]
# Enable or disable shadows. Bear in mind that this will force OpenMW to use shaders as if "[Shaders]/force shaders" was set to true.
enable shadows = false
# How many shadow maps to use - more of these means each shadow map texel covers less area, producing better looking shadows, but may decrease performance.
number of shadow maps = 3
# If true, allow shadow maps to overlap. Counter-intuitively, will produce better results when the light is behind the camera. When enabled, OpenMW uses Cascaded Shadow Maps and when disabled, it uses Parallel Split Shadow Maps.
allow shadow map overlap = true
# Indirectly controls where to split the shadow map(s). Values closer to 1.0 bring more detail closer to the camera (potentially excessively so), and values closer to 0.0 spread it more evenly across the whole viewing distance. 0.5 is recommended for most viewing distances by the original Parallel Split Shadow Maps paper, but this does not take into account use of a Light Space Perspective transformation, so other values may be preferable. If some of the terms used here go over your head, you might not want to change this, especially not without reading the associated papers first. When "allow shadow map overlap" is combined with a higher-than-default viewing distance, values closer to 1.0 will prevent nearby shadows losing a lot of quality.
split point uniform logarithmic ratio = 0.5
# Indirectly controls where to split the shadow map(s). Positive values move split points away from the camera and negative values move them towards the camera. Intended to be used in conjunction with changes to 'split point uniform logarithmic ratio' to counteract side effects, but may cause additional, more serious side effects. Read the Parallel Split Shadow Maps paper by F Zhang et al before changing.
split point bias = 0.0
# Enable the debug hud to see what the shadow map(s) contain.
enable debug hud = false
# Enable the debug overlay to see where each shadow map affects.
enable debug overlay = false
# Attempt to better use the shadow map by making them cover a smaller area. Especially helpful when looking downwards with a high viewing distance. The performance impact of this may be very large.
compute tight scene bounds = false
# How large to make the shadow map(s). Higher values increase GPU load, but can produce better-looking results. Power-of-two values may turn out to be faster on some GPU/driver combinations.
shadow map resolution = 1024
# Controls the minimum near/far ratio for the Light Space Perspective Shadow Map transformation. Helps prevent too much detail being brought towards the camera at the expense of detail further from the camera. Increasing this pushes detail further away.
minimum lispsm near far ratio = 0.25
# Used as the factor parameter for the polygon offset used for shadow map rendering. Higher values reduce shadow flicker, but risk increasing Peter Panning. See https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glPolygonOffset.xhtml for details.
polygon offset factor = 1.1
# Used as the units parameter for the polygon offset used for shadow map rendering. Higher values reduce shadow flicker, but risk increasing Peter Panning. See https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glPolygonOffset.xhtml for details.
polygon offset units = 4.0
# How far along the surface normal to project shadow coordinates. Higher values significantly reduce shadow flicker, usually with a lower increase of Peter Panning than the Polygon Offset settings. This value is in in-game units, so 1.0 is roughly 1.4 cm.
normal offset distance = 1.0
# Excludes theoretically unnecessary faces from shadow maps, slightly increasing performance. In practice, Peter Panning can be much less visible with these faces included, so if you have high polygon offset values, disabling this may help minimise the side effects.
use front face culling = true
# Allow actors to cast shadows. Potentially decreases performance.
actor shadows = false
# Allow the player to cast shadows. Potentially decreases performance.
player shadows = false
# Allow terrain to cast shadows. Potentially decreases performance.
terrain shadows = false
# Allow world objects to cast shadows. Potentially decreases performance.
object shadows = false
# Allow shadows indoors. Due to limitations with Morrowind's data, only actors can cast shadows indoors, which some might feel is distracting.
enable indoor shadows = true

Make sure to set the various types of shadows (actor, player, and so on) to "true" if you want these to cast shadows.

I can't really see a difference between your link and the settings suggested by CMAugust:

You should copy them from the shadows commit instead and see if that works, as those settings on the wiki are seriously out of date (for one thing, it's now "enable shadows" instead of simply "enabled").

The only computer I have available at the moment barely runs OpenMW without shaders, so it chokes on the shadows. Nevertheless, they seem to look good. Moreover: Documentation for the config is extremely good, which I appreciate

On my iMac, shadows turned on (actors, player, terrain, & objects on) with all other related settings at default values, the resulting shadows look pretty awful, especially when they move. I'll see about posting some screen shots.

On my iMac, shadows turned on (actors, player, terrain, & objects on) with all other related settings at default values, the resulting shadows look pretty awful, especially when they move. I'll see about posting some screen shots.

You can try experimenting with upping your shadow map resolution to 2048 or even 4096, and then also increase the number of shadow maps to 2 or 3. If this does not help, then yes, please post some screenshots.